Perl is a huge part of what I consider "work", but it also pleases me as a quick and dirty scripting language for doing things at home. I couldn't live without my dictionary-website-grabber script, or the script that tells me when the next train leaves. Without Perl, I'd have a hard time converting all sorts of text formats into eachother, both at home and at the office.

Home and work are hard to keep separated if you're a business owner. I often work at home, and do private coding at the office, so I couldn't decide between work and home. I chose "a keyboard" :)

As my job: yes;
When I can: yes;
In secret: sometimes;
For fun: yes;
Seriously: rarely;
4am: er, yea;
A keyboard: most always.